Raissi v Commissioner of Police

For an arrest under section 41 of the Terrorism Act 2000, legality turns on the arresting officer’s genuine suspicion and the objective reasonableness of the information actually in that officer’s mind. The wider source of that information need not ordinarily be disclosed. However, statutory restrictions under the Regulation of Investigatory Powers Act 2000 may prevent evidence revealing intercepted communications or the existence of interception warrants from being adduced. Evidence that falls within the statutory prohibition must be excluded, subject to the exceptional disclosure mechanism in section 18. Evidence that is irrelevant to the arresting officer’s state of mind is inadmissible independently of RIPA.

The claimants sought damages for wrongful arrest and false imprisonment after their arrests on 21 September 2001 on suspicion of involvement in terrorist attacks. The Commissioner relied on information received by the Metropolitan Police’s anti-terrorist branch. During preparation for trial, the claimants objected that parts of the defence and witness statements referred, directly or indirectly, to material potentially excluded by sections 17 and 18 of the Regulation of Investigatory Powers Act 2000.

The preliminary issue was whether the impugned material could be pleaded or admitted, whether the court should inspect it privately under section 18, and whether those questions should be postponed until trial.

1. The arresting officer’s state of mind was the material issue. Under section 41 of the Terrorism Act 2000, the officer had to possess a genuine suspicion and reasonable grounds for it. The relevant grounds were the information in the arresting officer’s mind when the power was exercised. The sources of that information were not themselves ordinarily material.
2. On the agreed hypothesis that the disputed intelligence derived from interception material, the unexpurgated passages in the statements of Mr Bunn and Mr MacBrayne fell within the prohibition in section 17 of the Regulation of Investigatory Powers Act 2000. Those passages had to be excluded, subject to section 18.
3. The remainder of the statements appeared inadmissible because the Commissioner accepted that they were immaterial to the arresting officers’ states of mind. Relevant evidence had to bear on an issue in the case; background evidence could not be admitted merely to provide a fuller narrative.
4. Section 18 permitted exceptional disclosure to the judge alone where the statutory conditions were satisfied. The guidance in Barracks v The Commissioner and Another [2006] EWCA Civ 1041 supported deciding whether such a course was necessary at the substantive hearing, after the available admissible evidence had been heard. The judge would be extremely reluctant to use an ex parte procedure unless it was the only means of achieving justice.
5. The court nevertheless had to rule at that stage on the disputed evidence. Deferring the issue would make the trial unmanageable. The trial was therefore to proceed on the basis of the admissible evidence, with the excised material excluded. The section 18 question and any application for a stay could be reconsidered if the trial showed that justice could not otherwise be achieved.